Mount Prospect, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

152
FXUS63 KLOT 040548
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1248 AM CDT Thu Jun 4 2026

.KEY MESSAGES...

- Potential for an increased fire danger on Thursday due to
  unseasonably warm, dry, and breezy conditions.

- Periodic shower and thunderstorm chances return Friday into
  Saturday and potentially into early next week.

&&

.DISCUSSION...
Issued at 200 PM CDT Wed Jun 3 2026

An upper level ridge, the central piece of an omega blocking
pattern over the CONUS, is projected to break down and slowly
move east through the end of the week. As this begins to occur
overnight tonight, broad southwesterly flow is expected to
slowly advect increasing moisture into the region. For tonight
and tomorrow, its main impact will be on increasing mid and high
level cloud cover. Despite these clouds, warmer air will
continue to advect in driving high temperatures tomorrow into
the mid 80s reaching all the way to the Lake Michigan shoreline.
Low level dry air will drop relative humidities down into the
20 percent range. With model soundings showing efficient mixing,
southwest surface winds are expected to become breezy with
gusts up to 25 mph. With the input from our local fire partners
commenting on the dry fuels around the area due to the lack of
wetting rainfall recently, there is the potential for an
elevated grass and brush fire danger setup for tomorrow.

As the ridge breaks down, a series of upper level shortwaves
will pass over the forecast area providing the next chances for
showers and storms. An initial lead wave is expected to move in
Friday morning and pass through the day. While cloud cover
could play a factor in reducing instability, showers and storms
that develop closer to the better forcing could potentially send
some outflow into the forecast area helping increase coverage.
While widespread severe storms are not expected, cannot rule out
some damaging wind gusts with any isolated stronger storm that
develops, though the better chances are in northwest Illinois.
While the higher water content looks to remain north of the
area, p-wats around 150 percent of normal leads to the potential
for isolated downpours. With drier antecedent conditions,
widespread flash flooding is not expected, though ponding on
roadways and low lying areas is possible.

The longer upper level wave is expected to move over and east
of the area on Saturday and another upper level ridge forms over
the central Plains. As it does, a surface cold front will move
south over the forecast area. Models are disagreeing on the
speed and distance southward that this boundary will move. So
there is lower confidence in when rain will end on Saturday,
though generally drier conditions are expected around and after
sunset. There is a non-zero chance that the front becomes quasi-
stationary by Sunday morning around or just south of US-24.
Blended PoPs kept a slight chance for rain in the southwestern
part of the forecast area on Sunday, with better chances in
west-central Illinois.

There is the chance for another short wave trough embedded in
the western side of the ridge to move northward over the Central
Plains early next week. Confidence is low in the chance that
this wave brings precipitation to the region, given that most
models are suggesting it phases with an upper level trough over
the Intermountain West as a pseudo omega block tries to form
once again over the CONUS. As moisture sloshes northward, there
are additional chances for showers early next week. But as the
ridge of the block strengthens over the eastern CONUS, warmer
and drier conditions are currently projected by midweek.

DK

&&

.AVIATION /06Z TAFS THROUGH 12Z FRIDAY/...
Issued at 1248 AM CDT Thu Jun 4 2026

There are no key concerns for the 06Z TAF period.

Light to near calm winds will veer from SE to favor SSW after
07Z. SSW winds will gust to around 20 kt after mid morning
Thursday and subside to below 10 kt for the evening. A system of
showers with associated MVFR will be moving in early Friday
just beyond the current 30-hr TAF period. VFR can be expected
throughout the period.

Doom

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.

&&

$$

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